Manufacture of cables



G. A. ANDEREGG MANUFACTURE OF CABLES Aug. 21, 1928. 1,681,566

Filed Aug. 26, 1924 Patented Aug. 21, 19281 UNITED s 'ra-'lasA PATENT .QFFIQE ,Cusrnvus A. ANDEREGG, 4or' n'ON'rCLAIn, nnwfasnsn, Assro'NOfa 'ro ,WESTERN ELECTRIC COMPANY, lmoonronarnn, OF NEW You, N. Y., A CORPORATION or NEW YORK.

Appncauon 11166 August 26, 16241h semi 166. 734,261.

This invention relates tos'ubmarine cables and more particularly to continuously loaded cables in which the loading material exhibits high permeability at low magnetizing force.

In the submarine cables which are continuously loaded with material lthe permeability of which varies when the materiall is strained, the loading material is'def'ormed by the extremely high Water pressure to which the cable is subjected when submerged and the inductance of the cable is thus changed. In order to overcome this difculty, it has been proposed to apply to a loaded conductor, underneath the insulation, a coating which is relatively fluid at tem-I peratures and pressures usually encountered in great depths of water to equalize the pressure upon all portions of the loading material. A compound suitable for this 'purpose is the well-known Chattertonscompounds or preferably a liquid bitumen consisting largely of malthenes of .natural origin and so refined as to be free from appreciable matter', volatile below 200 centigrade. this point, reference should be had to patent of 0. E. Buckley, No. 1,586,875, issued June 1,- 1926 and applic-ation of AVR. Kemp, filed February 7, 1923, Serial No. 617,511. Heretofore, vin `the application of the gutta perchaor other insulating material, in Order to insure a uniform thickness of the compound remaining on the conductor when it was passed through` the gutta percha eX- trusion machine, it was necessary to allow the compound to cool substantially to room temperature, otherwise, a non-uniform thickness of the compound resulted. This procedure, of course, has 'caused delay inl the delivery of the finished cable and has also required the provision of increased floor space to accommodate the cable until it has cooled substantially to room temperature. lin cases in which the conductor was passed through the gutta percha extrusion or cov- .'ering machine before having been allowed to cool to room temperature, it was found that the layer of compound yremaining on the surface of the conductor in the finished core was insuIic-ient and non-uniform. The reasons attributed to the existing condition were that the conductor was too warm, and

-the compound consequently being relatively For more detailed information on- MANUFACTUBE or. CABLES.'

I fluid, the pressure of the .gutta percha fo ced the relatively fluid compxound back along the conductor thereby prod cin a non-uniform .thickness of compound. Wien the conductor ,is somewhat ,colder and the compound correspondingly more stiff, the compound will be carried through the core tube of the covering machine and retained on the conductor as in that case the pressure of the gutta percha is less likely to force the compound back along the conductor.

1t is the object of the presentinvention to overcome the above-mentioned diliiculties heretofore encountered in the manufacture* of continuously loaded submarine cables. .This ohjectis accomplished by neutralizing the pressure resulting from the application of the gutta percha or other insulating ma-l terial, thereby making it possible to pass the conductor directly from the compound chamber to the covering machine. A

According to the above object, the present invention provides a method and means for making, it possible to apply the covering material, such as gutta ercha, immediatelyV following the passage o the conductor from the compound chamber without. requiring that the compound coated conductor be cooled to room temperature. The relatively fluid compound is subjected to pressure'by the use of apparatus which will supply the compound to the chamber at a regularuniform rate, irrespective of the viscosity of the compound which, of course, variesv with temperature. In accordance with the pre- .ferred form, the invention provides that the rate of flow of the compound will be regulated by the speed at which the conductor is advanced, and in, this Way control of the thickness of the applied coatin is effected. By placing the compound un er pressure, the pressure resulting from the application of the covering material will be neutralized and deformation of the relatively fluid compound thereby prevented.

. 1t is believed that a better understanding offtheinvention may be had from the following description ,.taken in conjunctionwith the accompanying drawing, which illustrates one embodimentof the invention.

Referring to the drawing, there is shown a conductor 4 which has previously had applied thereto a layer of loading material in the' form of a spirally laid Wire 0;'. tape, l

6 exhaust these chambers an to evacuate the interstices in the loaded conductor. As it is not practical to provide lpackings at the inlet,A of chamber 7 which wi very effectively seal against the entrance of air, because 10 of the nature of the conductor, it is diilicult to maintain a very high degree of vacuum in that chamber. There is leakage not only between the surface of the conduci tor and the packing, but also through the 4l5 conductor itself because such a conductor is in general nota single solid wire but'of a stranded construction. This vacuum can be improved to any desired degree by an arrangement of two or more vacuum cham bers in succession, as shown in the drawings# As previously stated, the drawing shows connected to the compound chamber 10 two vacuum chambers' and 7. Chamber 7 can obviously be maintained at a better vacuum because chamber 6 being partly evacuated,

the flow of air into the chamber 7 is less than if it opened directly to the air. The arrangement of the vacuum chambers could be extended to any desired number so that the vacuum in the one immediately preceding the compound chamber would `be maintained at a desired degree. Located just to the right of the chamber 7 is a third chamber 10 which has its inlet connected with a hopper 11 and which is completely filled with the compouwnd to be applied to the conductor. Arranged just below the hopper -11 are a pair of pressure rolls 12 and 13. These pressure rolls are continuously driven and function to force the compound from the hopper 11 into the channel 14. A pair of beveled gears 15 and 16 are mounted in the channel 14 and are arranged to be geared together at a point near te outlet while 15 at the inlet they are removed from each other. In this way the compound is prevented from being carried back into the channel. The gears 15 and 16 are driven from the same source of motive power which so draws the conductor 4, andthe compound from the channel 14 is forced into the chamber 10 through its intake. By having the gears 15 and 16 driven by the vsame source of motive power as that which advances the conductor to be covered, the compound is forced into the chamber 10 at a constant and uniform rate, just suliicient to apply the desired thickness of compound to the conductor. For eXample to provide a 0.006

50 inch layer on the surface of a conductor of an overalldiameter of 0.190 inch, there are required two hundred and seventy' cubic inches of compound per nautical mile of conductor. If, therefore, the conductor has f 5 no compound on itsA surface and has no va- 1,es1,56e 'n cant interstices when it enters the compound chamber, and if the compound is forced steadily and uniformly into that chamber at a rate of two hundred and seventy cubic inches per nautical mile of conductor, that amount will necessarily appear on the surface of the conductor in the completed core,

rovided the chamber is free from leaks and 1s compactly filled with compound throughout the operation. d

If the conductor has been previously com.- pounded, the packing through which the oonductor enters-the compound chamber might be made of -such dimensions as to remove all except a thin layer of the compound and the rate of delivery of the compound into the chamber would then be regulated to suit the additional amount required. Also, if the conductor is not solid but has spaces in itsinterior, asA is the case with the permalloy loaded conductor to which the present invention is especially applicable, ythe rate of delivery of compound into the cham-V ber might be increased by an amount Sullicient to fill the interstices within the conductor in addition to supplying the amount necessary for the desired surface layer.

The place where this uniform volume delivery would be most effective is,of course, the chamber connected directlywith the intake end of the core tube of the insulation extrusion machine. If the vacuum impregnating operation is to be combined with the covering operation, it might be found desirable to have two compound chambers following the 'vacuum chambers. In the first of the compound chambers the compound might be maintained under high pressureiny order to force it most effectively into the interstices of the conductor. The opening through which the conductor would pass from this chamber into the final compoundv chamber would then have such dimensions as to prevent more than a very thin layer of compound remaining on the surface of the conductor. The second compound chamber which would be connected directly to the extrusion machine, would then be the one to i which the compound would be delivered at l thel desired volume rate to provide the desired surface layer.

In order to facilitate the application of the compound an electric heater 17 may be arranged in connection with the chamber 10.V

The compound chamber 10 is directly connected to the gutta percha extrusion machine 18 by means of a core tube 19. The intake of they gutta per'cha extrusion 'machine is connected to a hopper 20 by a passage 21.

Located in the passage 21 are a pair of pres- A ure rolls 22 and 231 and gears 28 and 24. Both the rolls and thegears function in a manner similar to that described in connection with the application of the compound, The outlet'end of the gutta perche extrusion the compound back through the core tubeV 4notiamo.

machine is provided with an adjustable die 25 through which the loaded conductor passes andwhich is made adjustable to vary the opening between the end lof the core tube.,

.and the die to regulate the thickness of the gutta perclia ap lied;l 'Also Llocated in the main chamber o? the gutta percha extrusion machine is a screen 2'6, the purpose of which is to regulate or' govern the pressure `of the.

'gutta percha, thereby equalizing the pressure `on all sides of the conductor yand insuring a uniform thickness thereof. The lgutta percha covering machine 18 is also provided c with a heater 27 so-'tliat the temperature of the gut-ta pe-rclia may be controlled. The

.gear pumps shown for feeding Vthe compound so that the layer'of compound Willbe less than that corresponding tothe openingvof p the core tube. vHowever, With tlie compound under pressure, the force applied through the application of the gutta perclia Will be opposed by an equal and opposite force and the deformation 'of the compound thereby prevented. l u

. It is obviousthat' variousother types of machines. might be 4 used for applying the 'compound/and covering .material Without f departing from vthe spirit andtscope of the presentinvention.l What is claimed is: A

l. A continuous methodof insulating a composite conductor whichl comprises impregnating andcoating the conductor with a compound Which is relatively fluid 'at ordinary temperatures, and pressing a uniform layer of plasticv insulating material on to said relatively iiuid coating.

2. 'continuous method of insulating a composite conductor Which comprises .impregnating and coating said conductor by passing it through a compound which is semi-Huid at room temperature and is under a continuous and uniform pressure, and immediately thereafter applying a plastic insulatiiig material to the coated conductor.

3. A continuous method of insulating a composite conductor which comprises passing the composite conductor through a semiuid compound and applying .a continuous and uniform pressure to said compound to impregnate andjcoat said conductor with said compound and immediately thereafter applying a plastic `insulating material about thelcompouiidcoatjin' said compound-being semi-fluid during an after the Japplication of said insulatingjinaterial, and. said .presvsure being-in accordance with the thickness of the compound coating desired. p

4. continuous method of insulating a Acontinuously loaded conductor which com-fprises impregnating and coating said -con. ductor'by passing it through a' compound which is semi-fluid at room tem eratures and is under a continuous and uni orm pressure, ,l

and immediately thereafterapplying a plastic'in'sula'ting material to the coated conductor.

5. The metliodof continuous impregnation and insulation of a conductor with acontinuous layer of loading material thereon, which Aconsists in passing said conductor through. a 'semi-Huid compound, subjecting the compound to pressure sutliciently to lill the interstices f the conductor and form a` layer of said compound, and immediately and directly thereafter applying an insulat- .Y

ing material to the compound coated conductor.`

'6;' Thevfmethod ofl applying a relativelyv ,fluid compound and a coveringmaterial Ito 'a conductor in a continuous operation, which consists'in passing' the conductor through a relatively iuid compound subjected to pres sure, drawing the compound covered conductor through a covering material, and adjusting the pressure `of the" compound to neutralize the pressure exerted from the application of the covering material. l

7. A, continuous process of applying to a conductor an inner coating of semi-Huid ico compound and a layer of insulating maf terial, in which the conductor and said inner coat1ngprogress at the same rate of inl order that uniform thickness of said coating semi-fluid at ordinary temperatures.

8. The method of covering conductors,`

which consists4 in moving the conductor through a chamber, applying a uniform.

layer of relatively fluid compound thereto,

covering the coated conductor with an insulating material following the application of the compound, and neutralizing the pressure resulting from' the application of the insulating material whereby uniform thickness of the compound isV maintained.

9.' The method of manufacturing continuously loaded conductors which consists in moving the conductor through a chamber, forcinga compound into theinterstices of the loaded conductor and applying thereon a coating of a'compound which is semi-fluid at ordinary temperatures of a predetermined thickness, covering the coated conductor with an insulating .material immediately yfollowing the application of the semi-fluid coinpound, and neutralizing the pressure results n a n r speed as said layery of insulating material ing from the application ofthe insulating material to prevent deformation of the coating of semi-Huid compound.

l0. Ina covering machine, a chamberarranged to receive a conductor, a vrelatively fluid compound inl said chamber, means for continuously and uniformly supplying said compound to said chamber, said means being adjusted in accordance with the rate of travel of said conductor through said chamber, to apply a' uniform coating of the compound to the conductor having Tadesired thick! ness, and means for applying a plastic covering material to the coated conductor immediately following the passage of the conductor through the chamber containing the com-` having a desired thickness, and means for continuously applying a covering material to the coated conductor immediately following the ipassage of the conductor through the chamber containing the compound.

12. In a covering machine, a chamber arranged to receive a conductor, a semi-Huid compound contained in said chamber and adapted to be applied to .said conductor, a

channel through which' said' conductor passes, 'means for continuously pressing a plastic covering material on to the coated conductor at the extremity of said channel, and means to continuously neutralize the pressure exerted by the covering material whereby` deformation of the coating of said compound is prevented. l

'13, In/a coveringmachine, a chamber arranged to .receive a conductor, a semi-Huid compoupd contained in saidchamber, means A for continuously drawing lsaid conductor through said chamber, means for lapplying a layer of saidcompound to said conductor in accordance with the rate of travel of said conductor, means for pressing a.` covering of a plastic material on to the coated conductor immediately following the application of the compound, and means t neutralize the pressure exerted from the applil, cation of the covering material to prevent defamation of the said layer of compound.

14. In combination, a tapedconductor, a

chamber arranged to receive said taped conductor, means associated with said chamber for effecting the evacuation of the interstices of said'taped conductor, a second chamber following and in direct connection with said chamber, a relatively fluid compound contained in 'said second chamber and subjected to ressure whereb the interstices of said con uctor arelille with said compound, and whereby a coating of said com-l pound havingI a desired thickness is applied to said conductor, a covering machine, means for continuouslyl drawing said compound covered conductor through said covering niachine directly from said second mentioned chamber, means for applying covering to the coated conductor, and means for neu-l tralizing the pressure resulting from the application of the' covering matefial to prevent deformation of said coating of compound. A

In witness whereof, I hereunto subscribe 'my name this 25th day of August D.,

GUSTAVUS A. ANDEREGG. 

